Ventilator

ABSTRACT

A controllable slot ventilator has a housing and a closure member pivotably mounted on the housing to selectively close a vent in the housing. The closure member is supported on linking elements which are mounted on the closure member. The linking elements are arranged so as to rotate when the closure is moved between the open and closed position. The angle between a line, passing between the pivot points of the linking element, and the general plane of the closure member increases when the closure member moves to the open position.

BACKGROUND OF THE INVENTION

The present invention relates to ventilators, more particularly but notexclusively for use in rooms with sealed windows and/or double glazingwhere it is desirable to provide ventilation without having to open thewindow. This type of ventilation is now usually referred to as"secondary ventilation".

Secondary ventilation is often achieved by the insertion of a slotventilator into a slot cut or formed in the sash of a window, the slotconnecting through an air passage usually to the exterior of thebuilding. Air flow through the resulting ventilation passage iscontrolled by some sort of openable or closable ventilator such as a hitand miss ventilator or a parallel motion ventilator of the typedescribed in UK patent 1417751.

While the known type of parallel motion ventilator has been found to beexcellent in practice, there are certain specific situations in whichyet further improvements can be made. Firstly, it has been found thatthe "throw" of the ventilator, in other words the distance forward ofthe main ventilator body by which the facing strip or closure member hasto be moved in order fully to open the ventilator, can be furtherreduced by means of an improved linkage, making it even less likely fora user accidentally to snag the closure member when it is in the openposition. Furthermore, the applicants have now found a way to increasethe effective air opening of the ventilator without reducing its size.

The other type of known ventilator, the so called "hit and miss"ventilator , has to be relatively large in relation to its air openingsince the configuration of the ventilator itself cuts down the air flow.This type of ventilator comprises a fixed slotted panel mounted over anaperture, for example in a window sash, with a similar slotted panelarranged for sliding movement with respect to the fixed one. In the openposition of the ventilator the slots in the two panels line up, soallowing air to pass, whereas in the closed position the slots in onepanel line up with the bars between the slots of the other. As will beevident, the maximum air flow through a ventilator of this type is verysubstantially less than the maximum air flow which could otherwise flowthrough the aperture on which it is mounted; less than 50% would be atypical figure.

The known ventilators, then, if they are designed in order to allowthrough them a specified air flow, must be provided with an aperture inthe window which is larger than would actually be needed to support suchan air flow in the absence of the ventilator. This has tended to meanthat known ventilators, especially the hit and miss type are excessivelybulky for the air flow that they actually allow through. In recentyears, this problem has become more acute as manufacturers of timberwindows try to save as much timber as possible by providing only a verynarrow sash between the glass and the window frame. This has meant thatthe apertures in such sashes, which have to be provided withventilators, are now very narrow, with little space between the edge ofthe aperture and the frame for a bulky ventilator to be positioned. Inaddition, the head profiles of modern windows (that is the distancebetween the surface of the sash and the surface of the frame, in adirection perpendicular to the glass) are very narrow. For bothpractical and ascetic reasons it is not desirable to have any part ofthe ventilator, either in the open or in the closed position, whichextends forwardly of the surface of the frame. This of course restrictsthe length of the throw.

It is an object of the present invention at least to alleviate at leastsome of the difficulties of the prior art.

It is another object of the invention to provide a compact controllableventilator which allows through it all, or substantially all, of the airflow capable of passing through the aperture to be controlled.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided acontrollable slot ventilator comprising a main housing arranged forsecurement to the front face of a member having a vent to be controlled,the housing having first and second parallel side walls located, whenthe housing is so secured, forward of the said front face and definingtherebetween a slot in communication with the vent; and an elongateclosure member mounted for parallel motion between a closed positionobstructing the slot, and an open position, the closure member having aportion or portions which extend into the slot and to which arepivotally mounted parallel motion links, each link also being pivotallysecured with respect to the side walls of the housing, the linksrotating as the closure member is moved to the closed position so as toincrease the acute angle between a line passing between the pivot pointsof each link and the general plane of the closure member.

According to a second aspect of the invention there is provided acontrollable slot ventilator comprising a main housing arranged forsecurement to the front face of a member having a vent to be controlled,the housing having first and second parallel side walls located, whenthe housing is so secured, forward of the said front face and definingtherebetween a slot in communication with the vent; and an elongateclosure member mounted for parallel motion between a closed positionobstructing the slot, and an open position, the closure member having aportion or portions which extend into the slot and to which arepivotally mounted parallel motion links, each link also being pivotallysecured with respect to the side walls of the housing; the ventilatorhaving an air opening of at least 4000 mm² while having external housingdimensions of not more that 450 mm in length, and 30 mm in width; or ofat least 2000 mm² while having external housing dimensions of not morethan 270 mm in length, and 30 mm in width.

The ventilator may also be provided with an elongate ventilator hood,for securement to the rear side of the vent in the window or other ventmember. Preferably, the hood is shaped so as not to restrict the airflow that can pass through the vent. The rear exit from the vent may beprotected by means of a mesh, preferably a mesh which is suitably angledagain so as not to restrict the air flow.

In a particularly advantageous arrangement, the opening of the hood andthe opening of the housing of the ventilator are substantially equal,giving a "balanced" air flow. The ventilator may be shaped and sized forreception over, and closure of, a vent which will, when unobscured,allow substantially the "balanced" air flow to pass.

The invention may be carried into practice in a number of ways, and twospecific embodiments will now be described, by way of example, withreference to the drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a ventilator according to afirst embodiment of the present invention;

FIG. 2 is a similar drawing of a second embodiment;

FIG. 3 is a cross section through a ventilator hood, in position on awindow, suitable for use with the embodiments of FIG. 1 or FIG. 2; and

FIG. 4 is a cross section of the mesh shown schematically in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In this specification and in the claims air opening figures will begiven in square millimeters. A statement, for example, that a givenventilator has an air opening of 1000 mm² means that that ventilatorallows through it the amount of airflow that would pass through anentirely open aperture of 1000 mm² in size.

Also, in the specification and claims the "forward" direction will betaken to be a direction perpendicular to the aperture to be controlled,and towards that side of the aperture on which, in use, control of theventilator will be effected. This direction will often be perpendicularto the glass of the window in which the ventilator is to be secured,towards the interior of the room. The forward direction in the drawingsis shown by the arrow 1.

An exploded view of a ventilator according to a first embodiment of thepresent invention is shown in FIG. 1. The ventilator has an elongatemain housing 10 with mounting portions 12, 14 at the ends whereby theventilator can be secured to a window sash by means of screws (notshown) passing through screw holes 16, 18. Plugs 20,22 are provided forpositioning in the screw holes once the ventilator has been so secured,for cosmetic purposes.

Between the mounting portions 12, 14 are upper and lower elongate sidemembers 24, 26, defining between them an elongate slot or aperture 28.Spaced at intervals along the side members are first and second crosswalls 30 for strength. It will be appreciated, of course, that the upperand lower side members are in fact continuous and integral with themounting portions 12, 14, even though in the diagram they areschematically shown as being cutaway at 32, 34, 36 and 38.

In use, the ventilator will be secured to the front face (not shown) ofthe member containing the aperture to be controlled, with the aperturein that member lining up with the slot 28. Typically, the aperture to becontrolled will be in the timber sash of a window. Desirably, theaperture to be controlled is the same size and shape, or substantiallythe same size and shape, as the slot 28. Thus, as will be seen, theoverall size of the housing 10, particularly in a directionperpendicular to the length of the slot, which is the direction in whichthere is often very little space between the corresponding aperture inthe window sash and the surrounding window frame, is only very slightlylarger than the size of the slot itself. To ensure that the ventilatoris correctly positioned, the rear of the mounting portions 12, 14, havecorresponding mounting lugs 40,42 which are arranged to fit into theends of the aperture to be controlled. Further mounting lugs 44, 46 areprovided at the rear of the crosswalls 30. Positioned generally in frontof the main housing 10 is an elongate closure member 48 which ismanually operable by means of a handle 50 between a first position inwhich it seals the slot 28 and a second position in which it is spacedforwardly of the slot, so allowing air to pass through the slot andthrough the aperture in the window sash. The closure member is of coursecontinuous, although it is shown in the drawing as being cutaway at 58,60, 62. The closure member 48 comprises a generally flat sealing member52 having a rear surface adapted to seal against the front surface ofthe main housing 10. The rear surface of the sealing member has acentral upstanding rib (not shown) for strength, this rib being enlargedat two spaced positions along the sealing member to provide first andsecond mounting plates 54, 56, as shown. The sealing member, the rib andthe mounting plates may be integral with one another; alternatively,they may be separate members that are secured together.

Straddling the mounting plates 54, 56 are the parallel legs ofrespective linking members 64, 66. The linking member 64 is pivotallysecured to the mounting plate 54 by a pin 68 which is received within athroughbore 72 of the legs and, between the legs, through a throughbore74 of the mounting plate. A similar pin, (not shown) provides securementof the other linking member 66 to the mounting plate 56.

Pivoting of the linking member 66 with respect to its plate 56 islimited by a holding screw 74' which extends between holes 76 in theside members 24, 26, between them through holes 78 at the forward end ofthe legs of the linking member, and between them through a part-circularslot 80 in the mounting plate 56. The other linking member 64 issimilarly secured by another screw (not shown) received within the holes82 of the side members.

When the closure member 48 is in the closed position, the screw 74' isat the rearward end of the slot 80, with the sealing member 52 acting toseal the slot 28. To open the ventilator, the user applies pressure onthe handle 50, so moving the closure member 48 away from the mainhousing, with the linking members 64, 66 ensuring parallel movement. Inthe fully open position, the screw 74' comes to rest adjacent theforward end of the slot 80.

A gasket (not shown) is provided on the rear of the closure member toassist in sealing. When the ventilator is closed the user can push thehandle 50 so that the links 64, 66 move just over top dead centre, thusslightly compressing the gasket and providing a positive feel to theclosing movement.

In a second embodiment of the invention (FIG. 2) the integral housing 10of the first embodiment is replaced be separate mounting portions12',14' and side members 24',26'. The side members are secured to themounting portions by first and second end screws 84, only when one ofwhich is shown in FIG. 2. Once again, it will be appreciated that theside members and the closure member 48 are in fact continuous, althoughthey are shown in FIG. 2 as being cutaway at 86, 88 and 90.

In either embodiment the screw 74' or 84 could be replaced with amoulded or fixed pin or cross-member (not shown). This saves onmanufacturing costs, but means that an access channel has to be providedfrom the arcuate slot 80 to the outside of the mounting plate 54. 56 sothat the pin can be properly located within the slot. This pin can alsoact as a stop by abutting the plate when the ventilator is its openposition. With such an arrangement the links may be in two halves,manufactured to "click -fit" around the pin.

FIG. 3 shows how the rear of the aperture 86 in the window sash,generally on the outside of the window, is protected by an elongate hood88, shown here in cross section. The hood is secured by an elongateupper mounting flange 90 immediately above the opening to the aperture86, and extends outwardly and downwardly over it to protect the aperturefrom driving wind and rain. A V-shaped elongate metal mesh 32, shown indetail in FIG. 4, is secured to the underside of the hood by meshmounting flanges 94, 96. The V- shape of the mesh, and the spacingbetween the lower edge of the hood 88 and the closest point of thewindow frame are arranged so that there is no additional restriction tothe air flow 98 other than that which is inherent in the size of theaperture 86. In other words, even though the solid parts of the meshwill of course take up some of the cross sectional area, the overallcross sectional area that is displayed to the air flow 98 is at leastsubstantially as large as that of the aperture 86.

Alternatively (but not shown) the hood and mesh chould be moulded in onepiece from a plastics material.

The opposite ends of the hood are closed by generally quarter-circularend members (not shown).

In the embodiment of FIG. 1, the main parts of the ventilator, with theexception of the screws and the pins are preferably of an acetal resinmaterial, or of any other suitable generally rigid plastics material. Inthe second embodiment, of FIG. 2, additional rigidity has been providedby manufacturing the side members 24', 26', and the closure member 48,'of aluminium. The mounting portions 12',14' may be of any suitably rigidmaterial, either aluminium or a plastics material. The hood, shown inFIG. 3, is desirably of aluminium, though a hard plastics material couldbe used, while the hood end members (not shown) are of Delrin (trademark) The mesh 92, in the embodiment shown, has an open area of 68%.

With the specific embodiments shown the applicants have managed toprovide a ventilator having an air opening of 4000 mm², within a housingwhich has external dimensions of only 400 mm in length, 17 mm in heightand 11.5 mm in depth. Within this housing the internal dimensions of theslot 28 are 348 mm by 12.5 mm. A typical size for the slot in the windowsash is 353 mm by 12 mm, giving a total maximum air opening of 4236 mm².The specific ventilators described will allow through at least 94% ofthe maximum air flow, that is an air opening at least 4000 mm². An evensmaller aperture in the sash could be used, for example 12 mm by 348 mm,giving a maximum possible air opening of 4176 mm² ; in such a case, theventilator air opening of at least 4000 mm² represents over 951/2% ofthe maximum possible air opening.

Another embodiment (not shown) has a length of 255 mm and a slot lengthof 205 mm. The other dimensions being the same, this gives an air flowof about 2000 mm² for positioning over a vent of 355×13 mm.

Accordingly, it can be seen that an improved ventilator is disclosed. Alinkage arranged according to the invention is the opposite of thenormal parallel link arrangement, in which the said angle would decreaseas the closure member is moved to the closed position. The advantage isthat in the open position the link may be generally parallel to theplane of the closure member, rather than generally perpendicular as withthe prior art, so that the throw of the closure member may be relativelysmall. When the closure member is in the closed position the linejoining the two pivot points of the link may extend generallyperpendicular to the plane of the closure member, with the link thenextending backwardly from the side members into the vent. This extensionof the links into the vent does not of course act to reduce theeffective air opening, since the linkages may be designed so that theyonly extend in when the closure member is closed or almost closed.

Conveniently, the portion or portions of the closure member to which thelinks are pivotally secured comprises a rearwardly-extending rib or linkmounting plate. One end of the link is pivotally secured to the mountingplate, and the other end of the link is pivotally secured to the sidewalls by means of a pin which passes through an aperture or a cutawayportion of the plate. This aperture or cutaway portion may convenientlytake the form of a part-circular or arcuate guide slot, within which thepin moves as the closure member is moved between the open and closedpositions. The ends of this guide slot may act as stops, with the fullyopen position being defined by the abutment of the pin with the rear endof the slot, and the fully closed position by the abutment of the pinwith the front end of the slot.

The linking member may comprise first and second legs, between which, inuse, is received the rib or link mounting plate. In this way, the pinmay be arranged to pass through apertures in the side walls of thehousing, through apertures in the legs of the pin, and through thepart-circular or arcuate guide slot.

The housing of the ventilator may be secured to the front face of thevent member by any convenient means, such as screwing or gluing.Preferably, the housing has first and second end mounting portionshaving bores therein to receive the mounting screws. The first andsecond parallel side walls may be either integral with, or secured to,these end portions. Similarly, the rib or link mounting plates mayeither be integral with or secured to the closure member.

In order to assist in locating the housing with respect to the vent, themounting portions may include locating lugs which, in use, are arrangedto be received within the ends of the vent. Similar rearwardly-extendinglocating lugs may be provided on a cross wall or cross walls extendingbetween the parallel side walls.

Applicants have designed a controllable slot ventilator having anextremely large air opening for its small size. Preferably, indeed, theexterior dimensions of a 4000 mm² housing may be less than 420 mm by 20mm, more preferably approximately 400 mm by 17 mm. The depth of theparallel side walls (that is, the distance between the front edge of thehousing and the front face of the member to which it is attached in use)is not so critical: it is, however, preferably less than 20 mm, and moredesirably less than 15 mm. Most desirably, the depth is substantially11.5 mm.

The dimensions of a 2000 mm² housing are the same except for the length:this is preferably less than 260 mm, more preferably approximately 255mm.

The internal dimensions of a 4000 mm² slot, between the first and secondside walls of the housing, are desirably 348 mm by 12.5 mm or 13 mm,making the ventilator suitable for affixation over a vent ofapproximately this size. It is desirably sized so that when it ispositioned over a vent of about 348 mm by 12.5 mm the vent can beproperly sealed and at least 4000 mm² of air opening can be provided.For a 2000 mm² slot the length is preferably 210 mm².

Furthermore, the ventilator of the present invention should preferablybe capable of allowing to pass through it an air flow of at least 90%,or at least 93% of the corresponding air flow that would otherwise passthrough an aperture having the same internal dimensions as the internaldimensions of the ventilator slot.

We claim:
 1. A controllable slot ventilator comprising:a main housingadapted to be secured to a front face of a member having a vent to becontrolled, said housing having first and second parallel side wallslocated, when said housing is secured to the front of the member,forward of said front face, said side walls defining therebetween a slotin communication with the vent; and an elongate closure member mountedfor parallel motion between a closed position, obstructing said slot,and an open position, permitting air flow through said slot, saidclosure member having at least one portion which extends into said slot,parallel motion links mounted to said at least one portion at a firstpivot point and to said side walls at a second pivot point, saidparallel motion links rotating as the closure member is moved such thatan acute angle between a line passing through said first and secondpivot points of each of said links and the general plane of said closuremember increases as said closure member moves to said closed position.2. A ventilator as defined in claim 1, wherein, when said closure memberis in said closed position, said line passing through said first andsecond pivot points of each of said links extends generallyperpendicular to the plane of said closure member, with each respectivelink extending backwardly from said side walls into said vent.
 3. Aventilator as defined in claim 2 wherein said at least one portionincludes at least one rearwardly extending link-mounting plate and eachlink is pivotally secured to said at least one rearwardly extendinglink-mounting plate of said closure member.
 4. A ventilator as definedin claim 3 wherein each link is pivotally secured to said side walls bya respective pin which passes through an aperture of a respective one ofsaid plates.
 5. A ventilator as defined in claim 4 wherein said apertureor cutaway portion comprises an arcuate guide slot.
 6. A ventilator asdefined in claim 5 wherein said side walls and said pin are moulded froma plastic material.
 7. A ventilator as claimed in claim 6 wherein saidside walls and said pin are moulded as a single unit.
 8. A ventilator asdefined in claim 7 wherein an abutment of said plate and said pinprovides a stop for said closure member in its fully open position.
 9. Aventilator as defined in claim 8 wherein each link is manufactured intwo halves which snap-fit together to engage a respective pin.
 10. Acontrollable slot ventilator comprising a main housing adapted to beassembled to a front face of a member having a vent to be controlled,said housing including first and second parallel side walls definingtherebetween a slot communicating with said vent when said housing isassembled over the front face; and an elongate closure member mountedfor parallel motion between a closed position obstructing said slot, andan open position, said closure member having at least one portion whichextends into said slot, and links pivotally mounted to said closuremember and, pivotally secured to said side walls of said housing, theventilator having an air opening of at least 4000 mm² while havingexternal housing dimensions of not more than 450 mm² in length, and 30mm in width; or of at least 2000 mm² while having external housingdimensions of not more than 270 mm in length, and 30 mm in width.
 11. Aventilator as defined in claim 10 in combination with a ventilator hoodadapted to be positioned over said vent, the air openings of the hoodand ventilator being substantially equal.
 12. A ventilator as defined inclaim 1 wherein each said at least one portion includes at least onerearwardly extending link-mounting plate and said link is pivotallysecure to said at least one rearwardly-extending link-mounting plate ofthe closure member.
 13. A ventilator as defined in claim 1 wherein eachlink is pivotally secured to said sidewalls by a respective pin whichpasses through an aperture of a respective one of said plates.
 14. Aventilator as defined in claim 13 wherein said aperture comprises anarcuate guide slot.
 15. A ventilator as defined in claim 14 wherein saidside walls and said pin are molded from a plastic material.
 16. Aventilator as defined in claim 16 wherein said side walls and said pinare molded as a single unit.
 17. A ventilator as defined in claim 13wherein an abutment of said plate and said pin provides a stop for saidclosure member in its fully open position.
 18. A ventilator as definedin claim 13 wherein each link is manufactured in two-halves whichsnap-fit together to engage a respective pin.
 19. A ventilator asdefined in claim 1 in combination with a ventilator hood adapted to bepositioned over said vent opposite the ventilator, the air openings ofthe hood and ventilator being substantially equal.
 20. A ventilator asclaimed in claim 9 in combination with a ventilator hood adapted to bepositioned over said vent opposite the ventilator, the air openings ofthe hood and ventilator being substantially equal.
 21. A controllableslot ventilator comprising:a main housing adapted to be secured to afront face of a member having a vent to be controlled, said housinghaving first and second parallel side walls located, when said housingis secured to the front of said member forward of said front face, saidside walls defining therebetween a slot in communication with said vent;an elongate closure member mounted for parallel motion between a closedposition, obstructing said slot, and an open position, permitting airflow through said slot, said closure member having at least one portionwhich extends into said slot, said at least one portion includinggrooves; and parallel motion links mounted to said at least one portionat a first pivot point and to said side walls at a second pivot point,said parallel motion links including means for mounting said secondpivot point of each of said respective links on said side walls, each ofsaid mounting means positioned in a respective one of said grooves forsliding movement in said groove when said links pivot around theirrespective said first and second pivot points and said closure membermoves relative to said housing and between open and closed positions.22. A ventilator as defined in claim 2 wherein said at least one portionincludes at least one rearwardly extending link-mounting plate and eachlink is pivotally secured to said at least one rearwardly extendinglink-mounting plate of said closure member.
 23. A ventilator as definedin claim 4 wherein said groove is arcuate and said mounting means is apin which moves through said slot.